SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd04008bccf5b2580ef451d34088e874bc71481ef4022109580b75c6b73d01d0' 
  AND token = '6k5kKhZFvnnp94FCpNS8J7lj1NjR2lBz4gtuX/jz5Ig=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}